A plasma chamber is used to process substrates. For example, the plasma chamber is used to clean a wafer, or deposit materials, such as oxides, on the wafer, or etch the wafer, etc. During the processing of substrates, gas is supplied to the plasma chamber. A time in which the gas is supplied to the plasma chamber is important in switching between processes or in processing different wafers.
It is in this context that embodiments described in the present disclosure arise.